Can anyone elaborate to me on UV lights effects on a pond relating to koi, plants, and algae? I am considering adding one to my back yard pond to reduce algae but would like to know if there are any adverse effects to anything else I may have._________________Miss me?

They are effective and the lamped area is more than in an aquarium steriliser so they don't kill bacteria or pathogens,
You will need an extra prefilter layer to remove the dead algae from the filter. I use a piece of vetbed for this as it can be hosed down.

Some pond keepers forget that because the clarifer lights up it is working OK. Over time, the efficiency of the UV lamp will decline and require replacement. Check the user manual for periodic maintenance as well.